The present invention is in the building construction field and relates to windows and doors, particularly hinged windows and doors employing insulated glass panels. The invention is applicable to top hung, out-opening--bottom hung, in-opening--casement, in or out-opening--top hinged, in-opening, windows or doors.
The invention particularly relates to thermally insulated hinged windows or doors and similar panel assemblies for installation in a rough opening of an enclosed wall exposed to different temperature conditions at the opposite sides thereof.
The relatively high thermal conductivity of metals, such as aluminum or alloys thereof, is probably the most undesirable property limiting their substitution for wood and other less conductive non-metallic structural materials. The effect of this metal characteristic is best seen in windows or doors or other panel assemblies employing metal framing in direct conductive relationship with air at interior and exterior ambient temperatures giving rise to the generation and presence of frost and moisture condensation on the interior surfaces of the framing, especially in climates where extreme temperature differentials prevail. When a panel assembly has a metal outer frame fixed in the rough opening of a wall, and a sash movably mounted in such fixed outer frame with a metal frame peripherally embracing a glass or other panel, the thermal conductivity problem exists with respect to the metal sash frame as well as the metal outer or fixed frame.
A wide variety of solutions to overcome the deleterious high thermal conductivity of metal framing for windows, doors, and similar panel assemblies have been proposed with varying degrees of success. Most of the prior art constructions have included some type of thermal break or insulating barrier installed in an appropriate part of the outer metal frame and also in an appropriate part of the sash frame. Such constructions are often complex and difficult to fabricate as well as being relatively expensive. Examples of typical thermal barrier window or door assemblies or constructions may be found in U.S. Pat. Nos. 24,704; 3,055,648; 3,289,377; 3,302,354; 3,332,184; 3,393,487; 3,411,254; 3,420,026; 3,462,884; 3,487,580; 3,530,618; 3,600,857; and 3,780,473. As can readily be seen, thernal barrier constructions are made in numerous shapes and configurations and most require rather sophisticated fabrication.
Examples of hinged window constructions are illustrated by U.S. Pat. Nos. 3,686,795; 3,878,648; and 3,861,085. The first patent is of the thermally insulated casement type and utilizes several complex plastic and metal shapes to provide thermal insulation. The second patent discloses a structure designed to produce a frame concealed operating sash of increased strength, but does not provide thermal insulation between interior and exterior ambient temperatures. The third patent also relates to casement type windows and discloses a particular type of glazing construction as well as one type of thermal barrier. All of these constructions are difficult to fabricate.
It is a primary object of the present invention to provide a thermally insulated hinged type window, door or other panel of such construction that the outer frame overlaps the sash or panel to avoid exposure of the sash rail to either interior or exterior conditions and eliminates the need for a thermo-break or thermally insulated sash rail.
An important object of the instant invention is to provide a thermally insulated hinged window, door or the like, which has improved structural strength and which can be fabricated more economically.
Other objects and advantages of the invention will become readily apparent from a consideration of the description and drawings hereinafter.